Vestergaard Frandsen Chi Phan

Quality Assurance Acceptance Testing and Inspection for PermaNet® FAO/WHO/CIPAC Dublin June 2012

Start with why?

“The aim of procurement is to secure the best value for money for quality-assured products, to ensure the reliability of suppliers in terms of both quality and service” WHO Guidelines for Procuring Public Health Pesticides, 2012

LNs - Product Features

LNs - Product Specification(s)

Standard test method & Inspection

method

Sampling scheme

Go / No Go

Product Features - LNs

1. Protect against insect / vector entry

2. Be strong and durable

3. Keep its dimension after washing

4. Be safe to the users

5. Insecticide-treated properly for long lasting effectiveness

6. To be liked by the end-users, so they use it

Technical Consultation on specifications and quality control of netting materials and mosquitoes net – WHO 2005

Product Specification(s)

WHO specification

Active ingredient content

Release / Retention Index

Mesh count

Bursting strength

Dimensional Stability to washing

Storage Stability Accelerated test

Other guidelines / standards (non exhaustive list)

Size of the net

Weight (g/m2)

Free-azo dyestuffs & Color fastness to washing/rubbing/light

Flammability

Workmanship and Appearance

Other durability indicators (Slow nail test, tear strength, abrasion fastness…etc)

Storage Stability / Product Shelf life FINAL

Workmanship & Appearance – 1. Description …shall appear clean..free from visible matter and visible manufacturing defects…(WHO specification of LN)

Items Bursting Strength (kPa)

Mesh count (holes/inch2)

Slow nail test index (Wp) (N) -

100 D netting –Specification

>= 350 >= 156 n.a.

Netting – Conventional 380 (360-432)

169 28 (26.6-32)

Netting – New Machine 435 (430-440)

280 20 (19.9-21.8)

Photos: Courtesy of Bayer CropScience

Measure the right indicators, and measure them well

• Precision to Tolerance Ratio is the ratio of the precision of the measuring system to the allowed tolerance:

» USL: Upper Specification Limit » LSL: Lower Specification Limit

• A measure of whether a measurement system / a test method can discriminate between acceptable and unacceptable items. Highest Goal is to maintain P/T below 0.1. Secondary Goal is to maintain P/T below 0.3. P/T over 0.5 indicates ineffective measurement systems

The higher the P/T Ratio, the more producer and consumer loses

Measure the right indicators, and measure them well

Well measurement?

Deltamethrin content Requirement & CIPAC 333/LN test method

Tolerance ( in mg/m2) 41.25-68.75LSL ( in mg/m2) 41.25USL ( in mg/m2) 68.75Sigma of measurement ( in mg/m2) 0.6P/T ratio 0.13

Retention Index RI 01 Requirement & RI01 testTolerance min. 85%LSL 85%USL 100%Precision of the measurement (repeatability) 3.4%P/T ratio 1.36

ISO 2859 series and ISO 3951 series

ISO 2859-1:1999 series Sampling procedures for inspection by attributes –

ISO 3951-1:2005 series Sampling procedures for inspection by variables –

Equivalent national standards: ANSI/ASQC Z1.4 or Z1.9, NF06-022, BS 6001, DIN 40080; Military Standard 105E These standards provides guidance on sampling plan, i.e., number of samples taken with acceptability criteria and sampling scheme, i.e., sampling plans with switching rules. (Introduction to Statistical Quality Control, 4th Edition)

ISO 2859 / 3951 sampling plan with acceptability criteria

Proposals for further discussion

1. Product Specification(s) for LNs – Workmanship and Appearance (adoption of or development of UNICEF

defect definition for LN) 2. Apply Precision to Tolerance P/T Ratio in evaluating fitness of test method

for Quality control purpose. 3. Develop guidance / tool kits on application of ISO 2859 and ISO 3951 as an

annex of WHO Guidelines for Procuring Public Health Pesticides

Facts and Figures for PermaNet 2.0 and 3.0

1. Standardized:

• Manufacturing ISO 9001 certified

• Laboratories ISO 17025 accredited (2009)

• Inspection service ISO 17020 accredited (2012)

2. QA testing on 100% shipment as per ISO 2859 & ISO 3951

Measure the right indicators, and measure them well

.

A good measure: Description: Is quantitative The measure can be expressed as an objective value

Is easy to understand The measure conveys at a glance what it is measuring, and how it is derived

Encourages appropriate behavior The measure is balanced to reward productive behavior and discourage “game playing”

Is visible The effects of the measure are readily apparent to all involved in the process being measured

Is defined and mutually understood The measure has been defined by and/or agreed to by all key process participants (internally and externally)

Encompasses both outputs and inputs The measure integrates factors from all aspects of the process measured

Measures only what is important The measure focuses on a key performance indicator that is of real value to managing the process & product

Is multidimensional The measure is properly balanced between utilization, productivity, and performance, and shows the trade-offs

Uses economies of effort The benefits of the measure outweigh the costs of collection and analysis

Facilitates trust The measure validates the participation among the various parties

Keebler (1999)